aurweb.db: add query, create, delete helpers

Takes sqlalchemy kwargs or stanzas:

query(Model, Model.Column == value)
query(Model, and_(Model.Column == value, Model.Column != "BAD!"))

Updated tests to reflect the new utility and a comment about upcoming
function deprecation is added to get_account_type().

From here on, phase out the use of get_account_type().

+ aurweb.db: Added create utility function
+ aurweb.db: Added delete utility function

The `delete` function can be used to delete a record by search
kwargs directly.

Example:
    delete(User, User.ID == 6)

All three functions added in this commit are typically useful to
perform these operations without having to import aurweb.db.session.
Removes a bit of redundancy overall.

Signed-off-by: Kevin Morris <kevr@0cost.org>

test/test_user.py

@@ -1,5 +1,8 @@
 import pytest
 
+import aurweb.config
+
+from aurweb.db import query
 from aurweb.models.account_type import AccountType
 from aurweb.models.user import User
 from aurweb.testing import setup_test_db
@@ -26,7 +29,6 @@ def test_user():
         Salt="efgh", ResetKey="blahblah")
     session.add(user)
     session.commit()
-
     assert user in account_type.users
 
     # Make sure the user was created and given an ID.